Various types of storage devices are available to store data for electronic devices. Examples of storage devices include tape storage devices, disk storage devices, integrated circuit (IC) storage devices, and others.
In a linear tape storage device, data is stored on plural data tracks of a storage tape, where the data tracks extend generally longitudinally along the storage tape. The reading and recording of data in the data tracks is accomplished by using a tape head assembly, which typically includes magnetic read/write head elements for reading/recording data in the data tracks.
The storage tape is moved longitudinally with respect to the tape head assembly as the recording operation or read operation proceeds. Increasing tape storage density allows for a relatively larger amount of data to be stored on the storage tape (assuming the same storage tape size) and an increase in data access bandwidth (since a larger number of read and write head elements can concurrently access data at the same time).
However, various issues serve to limit the density of data tracks on a storage tape that can be effectively used in a tape storage device. Variations in manufacturing processes and equipment can cause variations in positions of head elements including read, write, and servo head elements during manufacture of a tape storage device. Some amount of physical tolerance has to be provided to account for such manufacturing variations, which means that off-track margins would have to be provided in data tracks to allow for variations in positions of the various head elements. Another issue that can lead to a limitation in the density of data tracks is tape tilt, which refers to the storage tape traveling across a tape head assembly at an angle (a non-zero angle from a longitudinal direction of travel). Off-track margins would also have to be provided on data tracks to account for tape tilt to ensure that head elements can accurately read or record information in the data tracks. There are also other contributors to the off-track margin that has to be provided in a data track.
The off-track margins basically specify that some amount of extra width is provided in each data track on a storage tape to allow a read or write head element to go off track by some amount and still be able to successfully perform a read or write operation. However, if the off-track margins are set too large, then the density of data tracks on a storage tape can be limited.